[Chest Tube is Unnecessary after Video-assisted Thoracoscopic Mediastinal Tumor Resection].

Of the 64 patients who underwent surgery for mediastinal tumors at our department from April 2019 to December 2022, 59 patients( 92.2%) underwent video-assisted thoracic surgery( VATS). Among the patients who underwent open surgery, 5 patients underwent median sternotomy and 1 patient underwent posterolateral thoracotomy. We usually perform 3-port VATS for mediastinal tumors. After surgery, patients are allowed to drink water after awakening from anesthesia, and they can have dinner on the day. If no lung resection is performed, we use a Nélaton catheter to remove air from the thoracic cavity and do not place a chest tube, and none had a chest tube insertion after surgery. As a result, postoperative pain was minimal, early ambulation was possible, and hospital stay was shortened.

A novel loop­mediated isothermal amplification method for efficient and robust detection of EGFR mutations.

The activation of somatic mutations conferring sensitivity to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors has been widely used in the development of advanced or metastatic primary lung cancer therapy. Therefore, identification of EGFR mutations is essential. In the present study, a loop­mediated isothermal amplification (LAMP) method was used to identify EGFR mutations, and its efficiency was compared with the Therascreen quantitative PCR assay. Using LAMP and Therascreen to analyze surgically resected tissue samples from patients with pulmonary adenocarcinoma, EGFR mutations were observed in 32/59 tumor samples (LAMP) and 33/59 tumor samples (Therascreen). Notably, the LAMP assay identified one tumor as wild­type, which had previously been identified as a deletion mutation in exon 19 via the Therascreen assay (Case X). However, the direct sequencing to confirm the EGFR status of the Case X adhered to the results of the LAMP assay. Further experiments using Case X DNA identified this exon 19 deletion mutation using both methods. In addition, a novel deletion mutation in exon 19 of the EGFR was identified. Overall, the present study shows that the LAMP method may serve as a valuable alternative for the identification oncogene mutations.

Inter-tumor heterogeneity of PD-L1 expression in non-small cell lung cancer.

BACKGROUND: The Dako PD-L1 immunohistochemistry (IHC) 22C3 pharmDx and the Dako 28-8 IHC pharmDx assays were approved by the US Food and Drug Administration, as a companion diagnostic test for pembrolizumab (Keytruda, Merk, Kenilworth, NJ, USA) and a complementary diagnostic test for nivolumab (Opdivo, Bristol Meyer Squibb, New York, NY, USA) in non-small cell lung cancer (NSCLC), respectively. Increased PD-L1 expression levels can be associated with greater therapeutic efficacy of pembrolizumab relative to other anti-PD-1 agents. However, in treatment decision making, little is known about which tissue (primary or metastatic lesion) should be stained by 22C3 antibody. We investigated the relationship between PD-L1 expression in primary tumors and paired metastatic lymph nodes using the 22C3 assay, and evaluated the concordance between the 22C3 and 28-8 assays. METHODS: PD-L1 expression was evaluated in cells from primary tumors and paired metastatic lymph nodes using the 22C3 and 28-8 IHC assays. Total 35 patients with primary tumor and paired metastatic lymph node were enrolled into this study, and all samples were surgically resected, formalin-fixed, and paraffin-embedded NSCLC tissues. Tumor cells exhibiting complete or partial membrane staining, were considered as PD-L1 positive. On the basis of tumor proportion score (TPS), all samples were classified as no expression (TPS: <1%), low expression (TPS: 1-49%), or high expression (TPS: ≥50%). RESULTS: TPS distribution was markedly different between primary tumors and paired metastatic lymph nodes. In 22C3 IHC assay, TPS similar to that of metastatic lymph nodes was demonstrated in 10 primary tumors, and concordance rate between them was 28.6%. Concurrently, in 28-8 IHC assay, 11 primary tumors had TPS similar to that of metastatic lymph nodes, with a concordance rate of 31.4%. CONCLUSIONS: TPS concordance rates (for both 22C3 and 28-8 antibodies) between primary tumors and paired lymph nodes were low. Inter-tumor heterogeneity of PD-L1 expression is an important issue for clinical oncologists during treatment planning.

[Present Status and Future Issues of Multidisciplinary Treatment of Lung Cancer from the Viewpoint of a Respiratory Surgeon].

With the advent of molecular targeted therapeutic agents and immunity checkpoint inhibitors, lung cancer drug therapy has advanced. We cannot expect to improve the performance of surgical treatment without drug therapy. The problem of improving the performance of surgical treatment for lung cancer is:① the role of surgery in multidisciplinary treatment for c-stageⅢ N2 lung cancer, ② post-operative adjuvant therapy, ③ multidisciplinary treatment of post-operative recurrence, ④ salvage surgery, and ⑤ sublobar resection in high risk cases. We will describe each of these with reference to our own experiences and literature considerations.

Recurrent thymoma with stiff-person syndrome and pure red blood cell aplasia.

Stiff-person syndrome (formerly known as stiff-man syndrome) is a very rare autoimmune and neurogenic disorder, thought to present as a paraneoplastic variant in association with thymoma. Pure red blood cell aplasia is also a paraneoplastic disorder associated with thymoma. Although separate cases of stiff-person syndrome and pure red blood cell aplasia have been reported, we describe here what is to our knowledge the first case of recurrent thymoma with both stiff-person syndrome and pure red blood cell aplasia. We describe the successful treatment of the neurogenic symptoms of stiff-person syndrome and the progressive anemia associated with pure red blood cell aplasia by tumor excision.